Grinder mechanism and process for boiler-furnaces and the like



c. J. DAVIDSON AND w. J. KENNEY. GRINDER MECHANISM AND PROCESS FOR BOILER FURNACES AND THE LlKE. APPLICATION FILED JAN. 4, I9I9.

1,372,65g Patent/ed Mar. 22, 1921i 2 SHEETSSHEET I.

C. J. DAVIDSON AND W. J. KENNEY. GRINDER MECHANISM AND PROCESS FOR BOILER FURNACES AND THE LIKE.

APPLICATION FILED JAN.4| I9I9.

Patented Mar. 22, 1921.

2 SHEETS-SHEEI 2.

CHARLES 3'. DAVIDSON, O1 TElL FH-LUKEE, WISCONSIN,

AND NILLl'AIJI 3'. KENNEY, OF

GHICAGO, ZLLENGIS, A$EIGNORS, IVIESNE ASSEGIIMENTS, TO MOLO CI-I CONEPANY, 0E KAUKATJNA, VIISCO'NSEN, B. CQRPORATION OF WISCONSIN.

GRINDER LIECHANISIJI AND 'PBOGESS "EOE BOELER-F'JBNACES AND THE LIKE.

Application filed January 12?. if; may concern:

)0 at? who Be it known that we, CHARLES J. DAVID- 10 present invention relates to grinder chanisni for boiler furnaces and the like.

of the general class herein deoinployed for removing the ref- 3: are use .UOm boiler furnaces, drying furnaces, *"naces of any description and purpose.

.cse grinders are frequently used in confJic-tion with automatic stokers, the ariigement being such that the grinders and the stokors automatically actuated, the furnace b4 n51 automatically fired by the sto and automatically cleaned of refuse by the grinders.

erctofore the main obstacle of the successfu use these grinders has been that of maintaining them due to the destructive action of high temperature of combustion. Preferably we provide a grinder on each side of the stoker retort so that as the fuel is coked and burned in the retort, the residue srreads out over the grinders, due to expansion and the feeding action of the stoker, and forms a bed of clinkers or slag on the grinders. in this position the grinders are subjected to an intense heat which tends to produce rapid depreciation, due to burning and cracking and mechanical difficulties incident to the large expansion and contraction due to heating. Numerous methods have been proposed for cooling these grinders, principally by air or steam, but such prior cooling methods have proven inadequate.

The primary object of our invention is to provide an improved grinder mechanism characterized by a simple and efiicient method of cooling. According to the preferred form of our invention we provide a shell or drum. adapted to be rotated and having studs or projections around the same Specification of Letters Eatent.

Patented Man 22, 1?;21.

1919. Serial 3T0. 289,711.

for breaking up and discharging the refuse as it is formed. The improved mode of cooling is effected by circulating water through the shell in such manner as to bring water in contact with that part of the grinder shell subject to the greatest heat. he circulating system, moreover, avoids any tendency to trap air or steam formed in the shell which would otherwise prevent the cooling water from reaching that part of the shell afld result in the burning of the grinder.

ln the accompanying drawings we have illustrated one preferred embodiment of our invention, adapted to the setting plan of a boiler furnace equipped with underfeed stokers It will be apparent, however, that this showing is merely exemplary, asthe grinders have utility with overfeed types of stokers as well and that their disposal in the furnace may be made parallel or crosswise to the stoker retorts or may lie on an incline to conform to the requirements imposed by the particular type of. stoker.

in the drawings:

Figure l is a front view partly in elevation and partly in section of a single stoker furnace equipped with our improved grinder mechanism i Fig. 2 is a longitudinal sectional view of one of the grinders or rotors taken on the line 22 of Fig. 1;

Fig. 3 is an elevational view of the same;

Fig. d is an enlarged sectional view through a portion of the grinder shell illustrating one of the studs for breaking up the clinkers.

The furnace illustrated in Fig. 1 is built up in the usual or any preferred manner and comprises the side walls 5, the rear bridge wall 6, the front panels 7 and the stoker retort 8, with the twyers 9 extending along the sides thereof. The twyers 9 are preferably sectionalized into a plurality of vertical units, namely the upper twyer ilccks 10, intermediate twyer apron members 12, thereby allowing for eX- pansion and contraction as will be apparent to those skilled in the art. The upper twyer blocks 10 are provided with a plurality of small air openings in the stepped portions 13 thereof. cured along the side walls 5, facing in opposition to the twyers 9, the draft holes of blocks 11 and these twyers opening toward the stoker retort 8. The twyers 14 also comprise upper twyer blocks, intermediate twyer blocks and apron members substantially as described in connection with the twyers 9. The apron members 12 of the twyers 9 cooperate with the apron members of the twyers 14 to form a longitudinal. pocket extending parallel to the retort 8 for receiving the clinkers and refuse therefrom, the lower portion of which pocket embraces a grinder cylinder 16. As shown in Fig. l the intermediate twyer blocks 11 are double walled, thereby providing an air circulating passage 15 about the longitudinal pocket formed by cooperation of the apron members of the twyers 9 and 14 respectively.

Coal is fed to the i'i'urnace through the usual hopper 17 which feeds into a ram cylinder discharging into the retort 8. The ram in this ram cylinder is periodically thrust past the hopper opening to ram a charge of coal into the retort under the action of a piston in the steam cylinder 18. As the coal works up to the top of the retort 8, it comes under the influence of the draft openings 19 and here: combustion is begun and stimulated by the forced draft through these openings. It will be noted that the retort 8 is inclosed by the ribbed 'plates 22 and the outer walls of the double walled intermediate twyer blocks 11, thereby forming an air circulating compartment about the retort. Air is forced into this compartment through the conduit 24 and passes up through the openings 25 in the upper twyer blocks 10 and out through the draft holes in the twyers.

The stoking action in the retort and the expansion in coking the coal results in the refuse at the top of the bed being discharged to each side of the retort into the grinder pockets between the center and side twyers. Here any remaining matter is driven ofl under the stimulation of a forced draft from the side and central twyers and from the natural. draft ensuing up through the grinding pocket from the ash hopper 26. The forced draft for the side twyers is supplied from a horizontal passageway 24 formed in the side wall 5 behind the twyer sections.

It will be noted from Fig. 8 that each grinder cylinder 16 is provided with a plurality of studs 27, arranged about its surface. It will be apparent that when these grinders are rotatedslightly the studs 27 will function to break up the masses of slag and clinkers forming above the grinders, and discharge them into the ash hopper 26. The grinders 16 are rotated in the proper direction to crush and discharge the clinkersbetween the grinders and the skirt portions 14 of the side twyers 12. It will be noted that the curved bottom. of the skirt portion 14 is eccentric with respect to the grinder ,by bolts 51, by

' cylinder 16, whereby a graduated discharge opening of decreasing area is formed between the two. This arrangement insures a thorough crushing of the clinkers.

The particular construction of the grinder 16 is shown in Fig. 2. Each grinder comprises a shell 28 which is closed oil at one end by a trunnion cap 29 and at the other end by a cap 31 having an extending sleeve portion 32. This sleeve 32'is formed with an integral flange 33 which is provided with lugs 34 on its radial face. The lugs 34 engage in recesses in the face of a coupling annulus 35 which has companion recesses in its other face, in which engage similar lugs 36 on the face of the radial flange 37; The flange 37 is formed integral with a reduced sleeve 38 which, at its end, supports the water connections for the cooling of the grinder, as we shall presently describe.

Each grinder unit has bearing support through the engagement of the trunnion cap 29 in a suitable bearing mounted in or adjacent the bridge wall 6, and through the engagement of the coupling annulus 35 in a suitable bearing in the front panel 7 of the furnace.

The sleeve 38 has a reduced threaded end which engages a coupling flange 43. The cooperating coupling flange 44 has a central opening through which extends a stufhng box sleeve 45. A collar 46 on the sleeve member 45 is engaged by a flange on the coupling member 44, which flange tends to retain the collar firmly against a packing ring 48. This packing ring is interposed between the collar 46 and a gland 49 on the coupling member 43. The sleeve member 45 has tapped holes into which thread the inlet and outlet pipes 52 and 53 respectively for circulating the cooling water through the grinder shell. The coupling 43-44 is provided to permit rotation between the sleeve member 45, which is held stationary by the pipes 52-53, and the reduced sleeve 38. The two membersof the coupling are joined the manipulation of which on the packing ring 48 may be adjusted to prevent leakage of water without causing undue friction between the rotating and stationary parts. The flanges 33 and 37 and the coupling 35 are provided with machined faces indicated at 39 and 4l, which are held firmly together by bolts 42 to secure a water tight connection between the same.

The sleeve member 45 is cored out with an internal rib or flange 45 which divides the interior into two chambers. A discharge pipe 54 threads into this flange and discharges the heated water from the grinder shell 28 into the closed chamber in the end of the sleeve member 45, from whence it is withdrawn through the outlet pipe. 53. The discharge pipe 54 is preferably pinned, as

the compression well as threaded, in the sleeve member to retain the discharge pipe stationary against the influence of the rotating grinder shell. The cold inlet water is fed through the pipe 52 into the open chamber in the other end of the sleeve 45, from whence it flows through the sleeves 32 and 38, cooling the latter, and into the shell 28 through the apertured tube 55. This tube is supported by threaded engagement in a bushing 56 which in turn threads into a flanged ring 57, which is bolted to the cap 31. The end of the tube is closed off by a reducing union 58, and to permit the discharge of the coolmg water into the shell 28 a'series of apertures 59 are provided about the periphery of A bushing 61 threads into the 58 and revolubly supports of the discharge pipe 5a. This discharge pipe taps into a T connection 62 adjacent the union 58, which T connection has an upwardly extending outlet pipe 63, and a downwardly extending weighted arm 64:. The outlet pipe 63 terminates near as is mechanically practicable to the inner periphery of the shell 28. The arm 64L has a weighted end, illustrated as a solid sphere 6%, which tends to hold the outlet pipe 63 uppermost. The weighted the tube 55. reducing union the other end arm functions to bring the outlet pipe 63 erect when the grinder is being installed, and by twisting the sleeve member 4.5 the pipe fitter can feel the influence of this weighted arm and thus connect the pipes 52 and 53 to rigidly hold the outlet pipe 63 in proper position.

From the foregoing it will be apparent that the shell 28 is substantially full of water or to the level of the outlet pipe 63. The outlet capacity of the pipe 63 is greater than the inlet capacity to the shell whereby the outlet pipe 63 is never sealed, and thus any steam generated in the shell or any air fed in with the inlet water is instantly vented through the outlet pipe 63. The outlet pipe by discharging the water adjacent the top of the shell, exhausts the water as soon as it becomes heated by contact with the upper surface of the shell. Thus the water is removed as fast as it becomes heatlhe inlet apertures 59 and the outlet pipe 63 are preferably disposed midway of the length of the shell 28 to afford a unim circulation to both ends of the shell. he large heat content of the cooling medium and the large conducting area be tween the shell and the medium prevent destructive heating of any part of the grinder.

operation both of the grinders are simultaneously; advanced a small angular distance by an intermittently reciproicated shaft 66 which extends across parallel to the front of the furnace as shown in Fig. 1. A ink 67 has a pin and slot connection with collar on the shaft 66 and at its upper end charge connection this link has operative connection with an advancing wheel 68 on the sleeve 38 (Fig. 2). The present invention is not concerned with this mechanism and we shall therefore not burden the description with the details of the same. Suiiice it to sa that the shaft 66 is intermittently reciprocated by a steam cylinder and functions to impart an advancing movement to the grinder cylinders for cleaning the furnace.

it will be noted from Fig. 1 that the inlet and outlet pipes, 52 and respectively have connection through valves 71 and 72 and up through pipes 73 and 74 with the inlet and outlet headers 7 5 and 76.

We claim:

1. In combination, a grinder for cleaning furnaces and the like, an inlet connection for feeding water into said grinder, a disfor discharging water from said grinder, and outlet means con nected to said discharge connection for exhausting the water from said grinder, said outlet means communicating with the up per part of said grinder only.

in combination. a grinder for cleaning furnaces and he like, an inlet-connection for feeding water into said rinder, a discharge connection for discharging water from said grinder, and outlet means conuecteu to said discharge connection for exhausting the water from said grinder at a point remote from the center of said grinder where vapor tends to form.

3. In combination, a grinder for cleaning furnaces and th like, an inlet connection for feeding water into said grinder, a discharge connection folr discharging water from said grinder, the water level in said grinder tending to form an air pocket therein, and outlet means in said grinder connected to said discharge connection, said outlet means opening into said air pocket.

in combination, a movable grinder element adapted for crushing and discharging clinkers from a furnace, an inlet connection for feeding water into said grinder, a discharge connection for discharging water from said grinder, and outlet means in said grinder connected to said discharge connection and communicating with that part of the grinder immediate to the furnace, said outlet means being stationary relative to said movable rinder.

5. In combination, a rotatable drum adapted for crushing and discharging clinkers from a furnace, an inlet pipe for feeding water in said drum, a discharge pipe for discharging water from said drum, said discharge pipe extending into the end of said drum, and an outlet pipe in said drum connected to said discharge pipe, said outlet pipe opening into the upper portion of said zllrum and being stationary relative to said rum.

movable relative to said grinder and adapt ed to occupy a predetermined position in said grinder, and means for indicating when said connection is in said predetermined position.

In combination, a grinder, means for circulating a cooling water through said grinder, said means comprising a water con nection adapted to open into the upper part of said grinder and a weight connected to said water connection and adapted to indicate when said water connection is in, the proper position.

9. In combination a rotatable grinder,-

comprising a hollow cylinder having closed ends, a pairof stationary water pipes connected at one end only of the cylinder, one or" said pipes beingadapted to discharge cooling water into one portion of the cylinder and the other pipe being adapted to withdraw the water from the highest portion of the cylinder only.

10. In combination a hollow cylinder having closing means at each end, said means comprising bearings, a pair of concentric tubes, one of said tubes extending through one of said closing means, means connec ed to the other tube for discharging water into one part of the cylinder and means connected to the said one tube for removin water from the upper portion of the body of water in the cylinder.

11. In combination a hollow rotatable cylinder having closing means at each end, said means comprising bearings, an axial tube extending into said cylinder and having means for withdrawing cooling water from the top of the cylinder, said tube being stationary, and means independent of said tube for introducing water into the cylinder.

12. In a device of the class described, a furnace, a hollow tube having a plurality of pins threaded into openings in the side walls thereof, a cap forclosing the outer end of the tube, said cap having a reduced portion forming a bearing, a reducing coupling secured to the other end of the tube, said reducing coupling forming another bearing, a second tube communicating at one end with the reducing coupling only and communicating at the other end with the central portion of the hollow tube only, a central axial tube extending through the reducing coupling and through the second tube, said axial tube being relatively stationary and having means for withdrawing cooling water from the peripheral part of the tube only. 7

13. The method of cooling a grinder havinga cylinder subjected to the heat or" a furnace which comprises feeding a stream of cool water to the central portion of the cylinder and causing it to circulate thereabout so to come in contact with the surfaces of the same, then exhausting the water at a point in the cylinder where air and steam accumulate so as to keep the water in contact with substantially the entire surface of.

the grinder.

"14.. In combination, a rotatable grinder, comprising a hollow cylinder having closed ends, means at one end only of said cylinder having a pair of passages, one of saidpassages being a supply passage for discharg ing cooling fluid into the cylinder, the other of said passages being a discharge passage for withdrawing the heated fluid from said cylinder at a point within the same.

In witness whereof we hereunto subscribe our names this 24 day of December 1918.

CHARLES J; DAVIDSON. WILLIAM J. KENNEY. 

